The Ignition Coil is located near the distributor in older applications, on top of the ignition control module in distributor-less ignition systems or as a coil-on-plug or coil-near-plug in
For What: The Ignition Coil supplies the needed voltage required to fire the spark
plug and complete the ignition cycle. The secondary output voltage from the ignition coil
is generated when the voltage in the ignition coil primary circuit is momentarily shorted
to ground and then open circuited. The magnetic field within the coil collapses when the
circuit opens inducing the voltage into the ignition coils secondary winding. The primary
circuit is controlled by the opening of the points or electronically by the Ignition Control
Module or PCM/ECM in newer applications. newer applications.
Failure Symptoms: Malfunction Indicator Light (MIL) illumination, failed emission test,
misfire condition, hard starting, no start, engine hesitation.
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